1. Field of the Invention
The present invention relates in general to the development of novel composite materials, and more particularly, to the development and use of novel nanocomposite anode materials to replace the carbon anode in lithium ion cells.
2. Description of the Relevant Art
Without limiting the scope of the invention, its background is described in connection with anode materials for lithium ion batteries. Lithium ion batteries have become the choice of power source for portable electronic devices such as cell phones, laptops, and PDAs due to their higher energy density compared to other rechargeable systems. They are also being intensively pursued for plug-in hybrid electric vehicles (PHEV) and electric vehicles (EV). Lithium ion batteries currently use graphite as the anode due to its excellent cycling behavior. However, the currently used carbon anode has the drawbacks of limited capacity (372 mAh/g) and safety concerns. Particularly, formation of solid-electrolyte interfacial (SEI) layer by a reaction of the carbon anode surface with the electrolyte and lithium plating in carbon anode arising from a charge/discharge potential close to that of Li/Li+ pose serious safety concerns. These difficulties have created enormous interest in the development of alternate anode materials.1−3 
U.S. Pat. No. 6,203,944 issued to Turner et al. (2001) provides electrode compositions suitable for use in secondary lithium batteries in which the electrode compositions have high initial capacities that are retained even after repeated cycling. The electrode compositions also exhibit high coulombic efficiencies. The electrode compositions, and batteries incorporating these compositions, are also readily manufactured. According to the '944 patent an electrode for a lithium battery that includes (a) an electrochemically active metal element which, prior to cycling, is in the form of an intermetallic compound or an elemental metal and (b) a non-electrochemically active metal element. The electrode has high initial capacities that are retained even after repeated cycling. The electrode also exhibits high coulombic efficiencies.
U.S. Pat. No. 6,949,312 issued to Kawakami and Asao (2005) discloses an electrode material for an anode of a rechargeable lithium battery, containing a particulate comprising an amorphous Sn-A-X alloy with a substantially non-stoichiometric ratio composition. For said formula Sn-A-X, A indicates at least one kind of an element selected from a group consisting of transition metal elements, X indicates at least one kind of an element selected from a group consisting of O, F, N, Mg, Ba, Sr, Ca, La, Ce, Si, Ge, C, P, B, Pb, Bi, Sb, Al, Ga, In, Tl, Zn, Be, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, As, Se, Te, Li and S, where the element X is not always necessary to be contained.